[PATCH v2 02/12] staging: comedi: adv_pci1710: don't check the chanlist twice
H Hartley Sweeten
hsweeten at visionengravers.com
Tue Apr 29 18:08:33 UTC 2014
The chanlist is checked in Step 5 of the (*do_cmdtest) there is no
reason to check it again in the (*do_cmd). The only reason its done
again is to get the actual 'seglen', the non-repeating length of the
chanlist.
Save the 'seglen' found by pci171x_ai_check_chanlist() in the private
data and use that in the (*do_cmd). Rename the private data member to
clarify it. Also, remove the unused 'act_chanlist_pos' member from the
private data.
Refactor the error handling in pci171x_ai_check_chanlist() so it returns
and errno for failure and 0 for success.
Signed-off-by: H Hartley Sweeten <hsweeten at visionengravers.com>
Reviewed-by: Ian Abbott <abbotti at mev.co.uk>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
drivers/staging/comedi/drivers/adv_pci1710.c | 34 ++++++++++++++--------------
1 file changed, 17 insertions(+), 17 deletions(-)
diff --git a/drivers/staging/comedi/drivers/adv_pci1710.c b/drivers/staging/comedi/drivers/adv_pci1710.c
index da1309b..f83c382 100644
--- a/drivers/staging/comedi/drivers/adv_pci1710.c
+++ b/drivers/staging/comedi/drivers/adv_pci1710.c
@@ -310,8 +310,7 @@ struct pci1710_private {
unsigned int ai_et_MuxVal;
unsigned int ai_et_div1, ai_et_div2;
unsigned int act_chanlist[32]; /* list of scanned channel */
- unsigned char act_chanlist_len; /* len of scanlist */
- unsigned char act_chanlist_pos; /* actual position in MUX list */
+ unsigned char saved_seglen; /* len of the non-repeating chanlist */
unsigned char da_ranges; /* copy of D/A outpit range register */
unsigned short ao_data[4]; /* data output buffer */
unsigned int cnt0_write_wait; /* after a write, wait for update of the
@@ -330,6 +329,7 @@ static int pci171x_ai_check_chanlist(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_cmd *cmd)
{
+ struct pci1710_private *devpriv = dev->private;
unsigned int chan0 = CR_CHAN(cmd->chanlist[0]);
unsigned int last_aref = CR_AREF(cmd->chanlist[0]);
unsigned int next_chan = (chan0 + 1) % s->n_chan;
@@ -337,8 +337,10 @@ static int pci171x_ai_check_chanlist(struct comedi_device *dev,
unsigned int seglen;
int i;
- if (cmd->chanlist_len == 1)
- return 1; /* seglen=1 */
+ if (cmd->chanlist_len == 1) {
+ devpriv->saved_seglen = cmd->chanlist_len;
+ return 0;
+ }
/* first channel is always ok */
chansegment[0] = cmd->chanlist[0];
@@ -353,7 +355,7 @@ static int pci171x_ai_check_chanlist(struct comedi_device *dev,
if (aref == AREF_DIFF && (chan & 1)) {
dev_err(dev->class_dev,
"Odd channel cannot be differential input!\n");
- return 0;
+ return -EINVAL;
}
if (last_aref == AREF_DIFF)
@@ -362,7 +364,7 @@ static int pci171x_ai_check_chanlist(struct comedi_device *dev,
dev_err(dev->class_dev,
"channel list must be continuous! chanlist[%i]=%d but must be %d or %d!\n",
i, chan, next_chan, chan0);
- return 0;
+ return -EINVAL;
}
/* next correct channel in list */
@@ -381,10 +383,12 @@ static int pci171x_ai_check_chanlist(struct comedi_device *dev,
CR_CHAN(cmd->chanlist[i % seglen]),
CR_RANGE(cmd->chanlist[i % seglen]),
CR_AREF(chansegment[i % seglen]));
- return 0;
+ return -EINVAL;
}
}
- return seglen;
+ devpriv->saved_seglen = seglen;
+
+ return 0;
}
static void setup_channel_list(struct comedi_device *dev,
@@ -396,9 +400,6 @@ static void setup_channel_list(struct comedi_device *dev,
struct pci1710_private *devpriv = dev->private;
unsigned int i, range, chanprog;
- devpriv->act_chanlist_len = seglen;
- devpriv->act_chanlist_pos = 0;
-
for (i = 0; i < seglen; i++) { /* store range list to card */
chanprog = muxonechan[CR_CHAN(chanlist[i])];
outw(chanprog, dev->iobase + PCI171x_MUX); /* select channel */
@@ -953,7 +954,6 @@ static int pci171x_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
struct pci1710_private *devpriv = dev->private;
struct comedi_cmd *cmd = &s->async->cmd;
unsigned int divisor1 = 0, divisor2 = 0;
- unsigned int seglen;
int mode;
if (cmd->convert_src == TRIG_TIMER) {
@@ -967,10 +967,8 @@ static int pci171x_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
start_pacer(dev, -1, 0, 0); /* stop pacer */
- seglen = pci171x_ai_check_chanlist(dev, s, cmd);
- if (seglen < 1)
- return -EINVAL;
- setup_channel_list(dev, s, cmd->chanlist, cmd->chanlist_len, seglen);
+ setup_channel_list(dev, s, cmd->chanlist, cmd->chanlist_len,
+ devpriv->saved_seglen);
outb(0, dev->iobase + PCI171x_CLRFIFO);
outb(0, dev->iobase + PCI171x_CLRINT);
@@ -1104,7 +1102,9 @@ static int pci171x_ai_cmdtest(struct comedi_device *dev,
/* Step 5: check channel list */
- if (!pci171x_ai_check_chanlist(dev, s, cmd))
+ err |= pci171x_ai_check_chanlist(dev, s, cmd);
+
+ if (err)
return 5;
return 0;
--
1.9.2
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